Commas, Semicolons, and Colons

When and how to use commas:

v Commas indicate direct quoted speech:
He said, “Let’s go,” and we did.
He said we should go, and we did.
v Commas go inside quotation marks:
He had heard about “oleo,” but he didn’t know what it was.
v Commas set off transitional phrases:
On the other hand, many diets decrease stamina and strength.
As a matter of fact, American football was derived from rugby.
Many people, however, are allergic to cats.
v Use commas for direct address, tag questions, mild interjections, and yes/no:
I hate to say this, John, but this relationship just isn’t working out.
You like chocolate, don’t you?
Well, I might have time for lunch with you next week.
Yes, you must do the homework.
v Commas come before coordinating conjunctions (for, and, nor, but, or, yet, so)
when they link two independent clauses:
It was raining, and I was hurrying to get home.
She felt terrible, but she went to class anyway.
v Commas follow introductory adverb clauses and introductory phrases:
On the way home, I stopped to buy groceries.
Because it was raining, I took a taxi home.
To our surprise, they were brothers.
v Commas separate items in a series, including coordinate adjectives:
He bought bananas, apples, oranges, and cheese.
She had long, dark, straight, thick hair.
v Commas set off nonrestrictive adjective clauses and other parenthetical elements:
My parents, who met each other in 1932, have been married for 50 years.
Hikers need sturdy shoes, which may be expensive.

When not to use commas:

v Do not separate dependent clauses (incomplete sentences):
Incorrect: Joe and Jill, went to the store.
Correct: Joe and Jill went to the store.
v Do not separate two elements:
Incorrect: I went home, and went to bed.
Correct: I went home and went to bed.
v Do not separate cumulative adjectives (Try inserting the word “and” or reversing the positions of the adjectives. If the sentence is confusing, do not use a comma):
Incorrect: I bought two, more apples.
Correct: I bought two more apples.

When and how to use semicolons:

v Semicolons connect two independent clauses (complete sentences) that are
closely related:
The book is informative; it has helpful charts and graphs.
My brother is going to Spain for the summer; he will be studying Spanish.
v Semicolons separate three or more items in a series that already have commas in them:
I like big, purple shirts; red, high-heeled shoes; and fluffy, yellow pillows.
I live with Larry, a student; Moe, an executive; a